/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2008 Blender Foundation.
 * All rights reserved.
 *
 *
 * Contributor(s): Blender Foundation
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/space_view3d/view3d_view.c
 *  \ingroup spview3d
 */

#include "DNA_camera_types.h"
#include "DNA_scene_types.h"
#include "DNA_object_types.h"

#include "MEM_guardedalloc.h"

#include "BLI_math.h"
#include "BLI_rect.h"
#include "BLI_utildefines.h"

#include "BKE_action.h"
#include "BKE_camera.h"
#include "BKE_context.h"
#include "BKE_depsgraph.h"
#include "BKE_object.h"
#include "BKE_global.h"
#include "BKE_main.h"
#include "BKE_report.h"
#include "BKE_scene.h"

#include "BIF_gl.h"

#include "UI_resources.h"

#include "GPU_select.h"

#include "WM_api.h"
#include "WM_types.h"

#include "ED_screen.h"

#ifdef WITH_GAMEENGINE
#  include "BLI_listbase.h"
#  include "BLI_callbacks.h"

#  include "GPU_draw.h"

#  include "BL_System.h"
#endif

#include "view3d_intern.h"  /* own include */

/* -------------------------------------------------------------------- */
/** \name Smooth View Operator & Utilities
 *
 * Use for view transitions to have smooth (animated) transitions.
 * \{ */

/* This operator is one of the 'timer refresh' ones like animation playback */

struct SmoothView3DState {
	float dist;
	float lens;
	float quat[4];
	float ofs[3];
};

struct SmoothView3DStore {
	/* source*/
	struct SmoothView3DState src;  /* source */
	struct SmoothView3DState dst;  /* destination */
	struct SmoothView3DState org;  /* original */

	bool to_camera;

	bool use_dyn_ofs;
	float dyn_ofs[3];

	/* When smooth-view is enabled, store the 'rv3d->view' here,
	 * assign back when the view motion is completed. */
	char org_view;

	double time_allowed;
};

static void view3d_smooth_view_state_backup(struct SmoothView3DState *sms_state,
                                            const View3D *v3d, const RegionView3D *rv3d)
{
	copy_v3_v3(sms_state->ofs,   rv3d->ofs);
	copy_qt_qt(sms_state->quat,  rv3d->viewquat);
	sms_state->dist            = rv3d->dist;
	sms_state->lens            = v3d->lens;
}

static void view3d_smooth_view_state_restore(const struct SmoothView3DState *sms_state,
                                             View3D *v3d, RegionView3D *rv3d)
{
	copy_v3_v3(rv3d->ofs,      sms_state->ofs);
	copy_qt_qt(rv3d->viewquat, sms_state->quat);
	rv3d->dist               = sms_state->dist;
	v3d->lens                = sms_state->lens;
}

/* will start timer if appropriate */
/* the arguments are the desired situation */
void ED_view3d_smooth_view_ex(
        /* avoid passing in the context */
        wmWindowManager *wm, wmWindow *win, ScrArea *sa,
        View3D *v3d, ARegion *ar, const int smooth_viewtx,
        const V3D_SmoothParams *sview)
{
	RegionView3D *rv3d = ar->regiondata;
	struct SmoothView3DStore sms = {{0}};
	bool ok = false;

	/* initialize sms */
	view3d_smooth_view_state_backup(&sms.dst, v3d, rv3d);
	view3d_smooth_view_state_backup(&sms.src, v3d, rv3d);
	/* if smoothview runs multiple times... */
	if (rv3d->sms == NULL) {
		view3d_smooth_view_state_backup(&sms.org, v3d, rv3d);
	}
	else {
		sms.org = rv3d->sms->org;
	}
	sms.org_view = rv3d->view;

	/* sms.to_camera = false; */  /* initizlized to zero anyway */

	/* note on camera locking, this is a little confusing but works ok.
	 * we may be changing the view 'as if' there is no active camera, but in fact
	 * there is an active camera which is locked to the view.
	 *
	 * In the case where smooth view is moving _to_ a camera we don't want that
	 * camera to be moved or changed, so only when the camera is not being set should
	 * we allow camera option locking to initialize the view settings from the camera.
	 */
	if (sview->camera == NULL && sview->camera_old == NULL) {
		ED_view3d_camera_lock_init(v3d, rv3d);
	}

	/* store the options we want to end with */
	if (sview->ofs)
		copy_v3_v3(sms.dst.ofs, sview->ofs);
	if (sview->quat)
		copy_qt_qt(sms.dst.quat, sview->quat);
	if (sview->dist)
		sms.dst.dist = *sview->dist;
	if (sview->lens)
		sms.dst.lens = *sview->lens;

	if (sview->dyn_ofs) {
		BLI_assert(sview->ofs  == NULL);
		BLI_assert(sview->quat != NULL);

		copy_v3_v3(sms.dyn_ofs, sview->dyn_ofs);
		sms.use_dyn_ofs = true;

		/* calculate the final destination offset */
		view3d_orbit_apply_dyn_ofs(sms.dst.ofs, sms.src.ofs, sms.src.quat, sms.dst.quat, sms.dyn_ofs);
	}

	if (sview->camera) {
		sms.dst.dist = ED_view3d_offset_distance(sview->camera->obmat, sview->ofs, VIEW3D_DIST_FALLBACK);
		ED_view3d_from_object(sview->camera, sms.dst.ofs, sms.dst.quat, &sms.dst.dist, &sms.dst.lens);
		sms.to_camera = true; /* restore view3d values in end */
	}

	/* skip smooth viewing for render engine draw */
	if (smooth_viewtx && v3d->drawtype != OB_RENDER) {
		bool changed = false; /* zero means no difference */

		if (sview->camera_old != sview->camera)
			changed = true;
		else if (sms.dst.dist != rv3d->dist)
			changed = true;
		else if (sms.dst.lens != v3d->lens)
			changed = true;
		else if (!equals_v3v3(sms.dst.ofs, rv3d->ofs))
			changed = true;
		else if (!equals_v4v4(sms.dst.quat, rv3d->viewquat))
			changed = true;

		/* The new view is different from the old one
		 * so animate the view */
		if (changed) {
			/* original values */
			if (sview->camera_old) {
				sms.src.dist = ED_view3d_offset_distance(sview->camera_old->obmat, rv3d->ofs, 0.0f);
				/* this */
				ED_view3d_from_object(sview->camera_old, sms.src.ofs, sms.src.quat, &sms.src.dist, &sms.src.lens);
			}
			/* grid draw as floor */
			if ((rv3d->viewlock & RV3D_LOCKED) == 0) {
				/* use existing if exists, means multiple calls to smooth view wont loose the original 'view' setting */
				rv3d->view = RV3D_VIEW_USER;
			}

			sms.time_allowed = (double)smooth_viewtx / 1000.0;

			/* if this is view rotation only
			 * we can decrease the time allowed by
			 * the angle between quats
			 * this means small rotations wont lag */
			if (sview->quat && !sview->ofs && !sview->dist) {
				/* scale the time allowed by the rotation */
				sms.time_allowed *= (double)fabsf(angle_signed_normalized_qtqt(sms.dst.quat, sms.src.quat)) / M_PI; /* 180deg == 1.0 */
			}

			/* ensure it shows correct */
			if (sms.to_camera) {
				/* use ortho if we move from an ortho view to an ortho camera */
				rv3d->persp = (((rv3d->is_persp == false) &&
				                (sview->camera->type == OB_CAMERA) &&
				                (((Camera *)sview->camera->data)->type == CAM_ORTHO)) ?
				                RV3D_ORTHO : RV3D_PERSP);
			}

			rv3d->rflag |= RV3D_NAVIGATING;

			/* not essential but in some cases the caller will tag the area for redraw,
			 * and in that case we can get a flicker of the 'org' user view but we want to see 'src' */
			view3d_smooth_view_state_restore(&sms.src, v3d, rv3d);

			/* keep track of running timer! */
			if (rv3d->sms == NULL) {
				rv3d->sms = MEM_mallocN(sizeof(struct SmoothView3DStore), "smoothview v3d");
			}
			*rv3d->sms = sms;
			if (rv3d->smooth_timer) {
				WM_event_remove_timer(wm, win, rv3d->smooth_timer);
			}
			/* TIMER1 is hardcoded in keymap */
			rv3d->smooth_timer = WM_event_add_timer(wm, win, TIMER1, 1.0 / 100.0); /* max 30 frs/sec */

			ok = true;
		}
	}

	/* if we get here nothing happens */
	if (ok == false) {
		if (sms.to_camera == false) {
			copy_v3_v3(rv3d->ofs, sms.dst.ofs);
			copy_qt_qt(rv3d->viewquat, sms.dst.quat);
			rv3d->dist = sms.dst.dist;
			v3d->lens = sms.dst.lens;

			ED_view3d_camera_lock_sync(v3d, rv3d);
		}

		if (rv3d->viewlock & RV3D_BOXVIEW) {
			view3d_boxview_copy(sa, ar);
		}

		ED_region_tag_redraw(ar);
	}
}

void ED_view3d_smooth_view(
        bContext *C,
        View3D *v3d, ARegion *ar, const int smooth_viewtx,
        const struct V3D_SmoothParams *sview)
{
	wmWindowManager *wm = CTX_wm_manager(C);
	wmWindow *win = CTX_wm_window(C);
	ScrArea *sa = CTX_wm_area(C);

	ED_view3d_smooth_view_ex(
	        wm, win, sa,
	        v3d, ar, smooth_viewtx,
	        sview);
}

/* only meant for timer usage */
static void view3d_smoothview_apply(bContext *C, View3D *v3d, ARegion *ar, bool sync_boxview)
{
	RegionView3D *rv3d = ar->regiondata;
	struct SmoothView3DStore *sms = rv3d->sms;
	float step, step_inv;

	if (sms->time_allowed != 0.0)
		step = (float)((rv3d->smooth_timer->duration) / sms->time_allowed);
	else
		step = 1.0f;

	/* end timer */
	if (step >= 1.0f) {

		/* if we went to camera, store the original */
		if (sms->to_camera) {
			rv3d->persp = RV3D_CAMOB;
			view3d_smooth_view_state_restore(&sms->org, v3d, rv3d);
		}
		else {
			view3d_smooth_view_state_restore(&sms->dst, v3d, rv3d);

			ED_view3d_camera_lock_sync(v3d, rv3d);
			ED_view3d_camera_lock_autokey(v3d, rv3d, C, true, true);
		}

		if ((rv3d->viewlock & RV3D_LOCKED) == 0) {
			rv3d->view = sms->org_view;
		}

		MEM_freeN(rv3d->sms);
		rv3d->sms = NULL;

		WM_event_remove_timer(CTX_wm_manager(C), CTX_wm_window(C), rv3d->smooth_timer);
		rv3d->smooth_timer = NULL;
		rv3d->rflag &= ~RV3D_NAVIGATING;
	}
	else {
		/* ease in/out */
		step = (3.0f * step * step - 2.0f * step * step * step);

		step_inv = 1.0f - step;

		interp_qt_qtqt(rv3d->viewquat, sms->src.quat, sms->dst.quat, step);

		if (sms->use_dyn_ofs) {
			view3d_orbit_apply_dyn_ofs(rv3d->ofs, sms->src.ofs, sms->src.quat, rv3d->viewquat, sms->dyn_ofs);
		}
		else {
			interp_v3_v3v3(rv3d->ofs, sms->src.ofs,  sms->dst.ofs,  step);
		}

		rv3d->dist = sms->dst.dist * step + sms->src.dist * step_inv;
		v3d->lens  = sms->dst.lens * step + sms->src.lens * step_inv;

		ED_view3d_camera_lock_sync(v3d, rv3d);
		if (ED_screen_animation_playing(CTX_wm_manager(C))) {
			ED_view3d_camera_lock_autokey(v3d, rv3d, C, true, true);
		}

		/* Event handling won't know if a UI item has been moved under the pointer. */
		WM_event_add_mousemove(C);
	}

	if (sync_boxview && (rv3d->viewlock & RV3D_BOXVIEW)) {
		view3d_boxview_copy(CTX_wm_area(C), ar);
	}

	/* note: this doesn't work right because the v3d->lens is now used in ortho mode r51636,
	 * when switching camera in quad-view the other ortho views would zoom & reset.
	 *
	 * For now only redraw all regions when smoothview finishes.
	 */
	if (step >= 1.0f) {
		WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
	}
	else {
		ED_region_tag_redraw(ar);
	}
}

static int view3d_smoothview_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
{
	View3D *v3d = CTX_wm_view3d(C);
	ARegion *ar = CTX_wm_region(C);
	RegionView3D *rv3d = ar->regiondata;

	/* escape if not our timer */
	if (rv3d->smooth_timer == NULL || rv3d->smooth_timer != event->customdata) {
		return OPERATOR_PASS_THROUGH;
	}

	view3d_smoothview_apply(C, v3d, ar, true);

	return OPERATOR_FINISHED;
}

/**
 * Apply the smoothview immediately, use when we need to start a new view operation.
 * (so we don't end up half-applying a view operation when pressing keys quickly).
 */
void ED_view3d_smooth_view_force_finish(
        bContext *C,
        View3D *v3d, ARegion *ar)
{
	RegionView3D *rv3d = ar->regiondata;

	if (rv3d && rv3d->sms) {
		rv3d->sms->time_allowed = 0.0;  /* force finishing */
		view3d_smoothview_apply(C, v3d, ar, false);

		/* force update of view matrix so tools that run immediately after
		 * can use them without redrawing first */
		Scene *scene = CTX_data_scene(C);
		ED_view3d_update_viewmat(scene, v3d, ar, NULL, NULL, NULL);
	}
}

void VIEW3D_OT_smoothview(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Smooth View";
	ot->description = "";
	ot->idname = "VIEW3D_OT_smoothview";

	/* api callbacks */
	ot->invoke = view3d_smoothview_invoke;

	/* flags */
	ot->flag = OPTYPE_INTERNAL;

	ot->poll = ED_operator_view3d_active;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Camera to View Operator
 * \{ */

static int view3d_camera_to_view_exec(bContext *C, wmOperator *UNUSED(op))
{
	View3D *v3d;
	ARegion *ar;
	RegionView3D *rv3d;

	ObjectTfmProtectedChannels obtfm;

	ED_view3d_context_user_region(C, &v3d, &ar);
	rv3d = ar->regiondata;

	ED_view3d_lastview_store(rv3d);

	BKE_object_tfm_protected_backup(v3d->camera, &obtfm);

	ED_view3d_to_object(v3d->camera, rv3d->ofs, rv3d->viewquat, rv3d->dist);

	BKE_object_tfm_protected_restore(v3d->camera, &obtfm, v3d->camera->protectflag);

	DAG_id_tag_update(&v3d->camera->id, OB_RECALC_OB);
	rv3d->persp = RV3D_CAMOB;

	WM_event_add_notifier(C, NC_OBJECT | ND_TRANSFORM, v3d->camera);

	return OPERATOR_FINISHED;

}

static bool view3d_camera_to_view_poll(bContext *C)
{
	View3D *v3d;
	ARegion *ar;

	if (ED_view3d_context_user_region(C, &v3d, &ar)) {
		RegionView3D *rv3d = ar->regiondata;
		if (v3d && v3d->camera && !ID_IS_LINKED(v3d->camera)) {
			if (rv3d && (rv3d->viewlock & RV3D_LOCKED) == 0) {
				if (rv3d->persp != RV3D_CAMOB) {
					return 1;
				}
			}
		}
	}

	return 0;
}

void VIEW3D_OT_camera_to_view(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Align Camera To View";
	ot->description = "Set camera view to active view";
	ot->idname = "VIEW3D_OT_camera_to_view";

	/* api callbacks */
	ot->exec = view3d_camera_to_view_exec;
	ot->poll = view3d_camera_to_view_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Camera Fit Frame to Selected Operator
 * \{ */

/* unlike VIEW3D_OT_view_selected this is for framing a render and not
 * meant to take into account vertex/bone selection for eg. */
static int view3d_camera_to_view_selected_exec(bContext *C, wmOperator *op)
{
	Main *bmain = CTX_data_main(C);
	Scene *scene = CTX_data_scene(C);
	View3D *v3d = CTX_wm_view3d(C);  /* can be NULL */
	Object *camera_ob = v3d ? v3d->camera : scene->camera;

	float r_co[3]; /* the new location to apply */
	float r_scale; /* only for ortho cameras */

	if (camera_ob == NULL) {
		BKE_report(op->reports, RPT_ERROR, "No active camera");
		return OPERATOR_CANCELLED;
	}

	/* this function does all the important stuff */
	if (BKE_camera_view_frame_fit_to_scene(bmain, scene, v3d, camera_ob, r_co, &r_scale)) {
		ObjectTfmProtectedChannels obtfm;
		float obmat_new[4][4];

		if ((camera_ob->type == OB_CAMERA) && (((Camera *)camera_ob->data)->type == CAM_ORTHO)) {
			((Camera *)camera_ob->data)->ortho_scale = r_scale;
		}

		copy_m4_m4(obmat_new, camera_ob->obmat);
		copy_v3_v3(obmat_new[3], r_co);

		/* only touch location */
		BKE_object_tfm_protected_backup(camera_ob, &obtfm);
		BKE_object_apply_mat4(camera_ob, obmat_new, true, true);
		BKE_object_tfm_protected_restore(camera_ob, &obtfm, OB_LOCK_SCALE | OB_LOCK_ROT4D);

		/* notifiers */
		DAG_id_tag_update(&camera_ob->id, OB_RECALC_OB);
		WM_event_add_notifier(C, NC_OBJECT | ND_TRANSFORM, camera_ob);
		return OPERATOR_FINISHED;
	}
	else {
		return OPERATOR_CANCELLED;
	}
}

void VIEW3D_OT_camera_to_view_selected(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Camera Fit Frame to Selected";
	ot->description = "Move the camera so selected objects are framed";
	ot->idname = "VIEW3D_OT_camera_to_view_selected";

	/* api callbacks */
	ot->exec = view3d_camera_to_view_selected_exec;
	ot->poll = ED_operator_scene_editable;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Object as Camera Operator
 * \{ */

static void sync_viewport_camera_smoothview(bContext *C, View3D *v3d, Object *ob, const int smooth_viewtx)
{
	Main *bmain = CTX_data_main(C);
	for (bScreen *screen = bmain->screen.first; screen != NULL; screen = screen->id.next) {
		for (ScrArea *area = screen->areabase.first; area != NULL; area = area->next) {
			for (SpaceLink *space_link = area->spacedata.first; space_link != NULL; space_link = space_link->next) {
				if (space_link->spacetype == SPACE_VIEW3D) {
					View3D *other_v3d = (View3D *)space_link;
					if (other_v3d == v3d) {
						continue;
					}
					if (other_v3d->camera == ob) {
						continue;
					}
					if (v3d->scenelock) {
						ListBase *lb = (space_link == area->spacedata.first)
						                   ? &area->regionbase
						                   : &space_link->regionbase;
						for (ARegion *other_ar = lb->first; other_ar != NULL; other_ar = other_ar->next) {
							if (other_ar->regiontype == RGN_TYPE_WINDOW) {
								if (other_ar->regiondata) {
									RegionView3D *other_rv3d = other_ar->regiondata;
									if (other_rv3d->persp == RV3D_CAMOB) {
										Object *other_camera_old = other_v3d->camera;
										other_v3d->camera = ob;
										ED_view3d_lastview_store(other_rv3d);
										ED_view3d_smooth_view(
										        C, other_v3d, other_ar, smooth_viewtx,
										        &(const V3D_SmoothParams) {
										            .camera_old = other_camera_old,
										            .camera = other_v3d->camera,
										            .ofs = other_rv3d->ofs,
										            .quat = other_rv3d->viewquat,
										            .dist = &other_rv3d->dist,
										            .lens = &other_v3d->lens});
									}
									else {
										other_v3d->camera = ob;
									}
								}
							}
						}
					}
				}
			}
		}
	}
}

static int view3d_setobjectascamera_exec(bContext *C, wmOperator *op)
{
	View3D *v3d;
	ARegion *ar;
	RegionView3D *rv3d;

	Scene *scene = CTX_data_scene(C);
	Object *ob = CTX_data_active_object(C);

	const int smooth_viewtx = WM_operator_smooth_viewtx_get(op);

	/* no NULL check is needed, poll checks */
	ED_view3d_context_user_region(C, &v3d, &ar);
	rv3d = ar->regiondata;

	if (ob) {
		Object *camera_old = (rv3d->persp == RV3D_CAMOB) ? V3D_CAMERA_SCENE(scene, v3d) : NULL;
		rv3d->persp = RV3D_CAMOB;
		v3d->camera = ob;
		if (v3d->scenelock)
			scene->camera = ob;

		/* unlikely but looks like a glitch when set to the same */
		if (camera_old != ob) {
			ED_view3d_lastview_store(rv3d);

			ED_view3d_smooth_view(
			        C, v3d, ar, smooth_viewtx,
			        &(const V3D_SmoothParams) {
			            .camera_old = camera_old, .camera = v3d->camera,
			            .ofs = rv3d->ofs, .quat = rv3d->viewquat,
			            .dist = &rv3d->dist, .lens = &v3d->lens});
		}

		if (v3d->scenelock) {
			sync_viewport_camera_smoothview(C, v3d, ob, smooth_viewtx);
			WM_event_add_notifier(C, NC_SCENE, scene);
		}
		WM_event_add_notifier(C, NC_OBJECT | ND_DRAW, scene);
	}

	return OPERATOR_FINISHED;
}

bool ED_operator_rv3d_user_region_poll(bContext *C)
{
	View3D *v3d_dummy;
	ARegion *ar_dummy;

	return ED_view3d_context_user_region(C, &v3d_dummy, &ar_dummy);
}

void VIEW3D_OT_object_as_camera(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Set Active Object as Camera";
	ot->description = "Set the active object as the active camera for this view or scene";
	ot->idname = "VIEW3D_OT_object_as_camera";

	/* api callbacks */
	ot->exec = view3d_setobjectascamera_exec;
	ot->poll = ED_operator_rv3d_user_region_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Window and View Matrix Calculation
 * \{ */

/**
 * \param rect optional for picking (can be NULL).
 */
void view3d_winmatrix_set(ARegion *ar, const View3D *v3d, const rcti *rect)
{
	RegionView3D *rv3d = ar->regiondata;
	rctf viewplane;
	float clipsta, clipend;
	bool is_ortho;

	is_ortho = ED_view3d_viewplane_get(v3d, rv3d, ar->winx, ar->winy, &viewplane, &clipsta, &clipend, NULL);
	rv3d->is_persp = !is_ortho;

#if 0
	printf("%s: %d %d %f %f %f %f %f %f\n", __func__, winx, winy,
	       viewplane.xmin, viewplane.ymin, viewplane.xmax, viewplane.ymax,
	       clipsta, clipend);
#endif

	if (rect) {  /* picking */
		rctf r;
		r.xmin = viewplane.xmin + (BLI_rctf_size_x(&viewplane) * (rect->xmin / (float)ar->winx));
		r.ymin = viewplane.ymin + (BLI_rctf_size_y(&viewplane) * (rect->ymin / (float)ar->winy));
		r.xmax = viewplane.xmin + (BLI_rctf_size_x(&viewplane) * (rect->xmax / (float)ar->winx));
		r.ymax = viewplane.ymin + (BLI_rctf_size_y(&viewplane) * (rect->ymax / (float)ar->winy));
		viewplane = r;
	}

	if (is_ortho) {
		wmOrtho(viewplane.xmin, viewplane.xmax, viewplane.ymin, viewplane.ymax, clipsta, clipend);
	}
	else {
		wmFrustum(viewplane.xmin, viewplane.xmax, viewplane.ymin, viewplane.ymax, clipsta, clipend);
	}

	/* update matrix in 3d view region */
	glGetFloatv(GL_PROJECTION_MATRIX, (float *)rv3d->winmat);
}

static void obmat_to_viewmat(RegionView3D *rv3d, Object *ob)
{
	float bmat[4][4];

	rv3d->view = RV3D_VIEW_USER; /* don't show the grid */

	normalize_m4_m4(bmat, ob->obmat);
	invert_m4_m4(rv3d->viewmat, bmat);

	/* view quat calculation, needed for add object */
	mat4_normalized_to_quat(rv3d->viewquat, rv3d->viewmat);
}

/**
 * Sets #RegionView3D.viewmat
 *
 * \param scene: Scene for camera and cursor location.
 * \param v3d: View 3D space data.
 * \param rv3d: 3D region which stores the final matrices.
 * \param rect_scale: Optional 2D scale argument,
 * Use when displaying a sub-region, eg: when #view3d_winmatrix_set takes a 'rect' argument.
 *
 * \note don't set windows active in here, is used by renderwin too.
 */
void view3d_viewmatrix_set(
        Scene *scene,
        const View3D *v3d, RegionView3D *rv3d, const float rect_scale[2])
{
	if (rv3d->persp == RV3D_CAMOB) {      /* obs/camera */
		if (v3d->camera) {
			BKE_object_where_is_calc(scene, v3d->camera);
			obmat_to_viewmat(rv3d, v3d->camera);
		}
		else {
			quat_to_mat4(rv3d->viewmat, rv3d->viewquat);
			rv3d->viewmat[3][2] -= rv3d->dist;
		}
	}
	else {
		bool use_lock_ofs = false;


		/* should be moved to better initialize later on XXX */
		if (rv3d->viewlock & RV3D_LOCKED)
			ED_view3d_lock(rv3d);

		quat_to_mat4(rv3d->viewmat, rv3d->viewquat);
		if (rv3d->persp == RV3D_PERSP) rv3d->viewmat[3][2] -= rv3d->dist;
		if (v3d->ob_centre) {
			Object *ob = v3d->ob_centre;
			float vec[3];

			copy_v3_v3(vec, ob->obmat[3]);
			if (ob->type == OB_ARMATURE && v3d->ob_centre_bone[0]) {
				bPoseChannel *pchan = BKE_pose_channel_find_name(ob->pose, v3d->ob_centre_bone);
				if (pchan) {
					copy_v3_v3(vec, pchan->pose_mat[3]);
					mul_m4_v3(ob->obmat, vec);
				}
			}
			translate_m4(rv3d->viewmat, -vec[0], -vec[1], -vec[2]);
			use_lock_ofs = true;
		}
		else if (v3d->ob_centre_cursor) {
			float vec[3];
			copy_v3_v3(vec, ED_view3d_cursor3d_get(scene, (View3D *)v3d));
			translate_m4(rv3d->viewmat, -vec[0], -vec[1], -vec[2]);
			use_lock_ofs = true;
		}
		else {
			translate_m4(rv3d->viewmat, rv3d->ofs[0], rv3d->ofs[1], rv3d->ofs[2]);
		}

		/* lock offset */
		if (use_lock_ofs) {
			float persmat[4][4], persinv[4][4];
			float vec[3];

			/* we could calculate the real persmat/persinv here
			 * but it would be unreliable so better to later */
			mul_m4_m4m4(persmat, rv3d->winmat, rv3d->viewmat);
			invert_m4_m4(persinv, persmat);

			mul_v2_v2fl(vec, rv3d->ofs_lock, rv3d->is_persp ? rv3d->dist : 1.0f);
			vec[2] = 0.0f;

			if (rect_scale) {
				/* Since 'RegionView3D.winmat' has been calculated and this function doesn't take the 'ARegion'
				 * we don't know about the region size.
				 * Use 'rect_scale' when drawing a sub-region to apply 2D offset,
				 * scaled by the difference between the sub-region and the region size.
				 */
				vec[0] /= rect_scale[0];
				vec[1] /= rect_scale[1];
			}

			mul_mat3_m4_v3(persinv, vec);
			translate_m4(rv3d->viewmat, vec[0], vec[1], vec[2]);
		}
		/* end lock offset */
	}
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name OpenGL Select Utilities
 * \{ */

/**
 * Optionally cache data for multiple calls to #view3d_opengl_select
 *
 * just avoid GPU_select headers outside this file
 */
void view3d_opengl_select_cache_begin(void)
{
	GPU_select_cache_begin();
}

void view3d_opengl_select_cache_end(void)
{
	GPU_select_cache_end();
}

/**
 * \warning be sure to account for a negative return value
 * This is an error, "Too many objects in select buffer"
 * and no action should be taken (can crash blender) if this happens
 *
 * \note (vc->obedit == NULL) can be set to explicitly skip edit-object selection.
 */
int view3d_opengl_select(
        ViewContext *vc, unsigned int *buffer, unsigned int bufsize, const rcti *input,
        eV3DSelectMode select_mode)
{
	struct bThemeState theme_state;
	Scene *scene = vc->scene;
	View3D *v3d = vc->v3d;
	ARegion *ar = vc->ar;
	rcti rect;
	int hits;
	const bool use_obedit_skip = (scene->obedit != NULL) && (vc->obedit == NULL);
	const bool is_pick_select = (U.gpu_select_pick_deph != 0);
	const bool do_passes = (
	        (is_pick_select == false) &&
	        (select_mode == VIEW3D_SELECT_PICK_NEAREST) &&
	        GPU_select_query_check_active());
	const bool use_nearest = (is_pick_select && select_mode == VIEW3D_SELECT_PICK_NEAREST);

	char gpu_select_mode;

	/* case not a border select */
	if (input->xmin == input->xmax) {
		/* seems to be default value for bones only now */
		BLI_rcti_init_pt_radius(&rect, (const int[2]){input->xmin, input->ymin}, 12);
	}
	else {
		rect = *input;
	}

	if (is_pick_select) {
		if (is_pick_select && select_mode == VIEW3D_SELECT_PICK_NEAREST) {
			gpu_select_mode = GPU_SELECT_PICK_NEAREST;
		}
		else if (is_pick_select && select_mode == VIEW3D_SELECT_PICK_ALL) {
			gpu_select_mode = GPU_SELECT_PICK_ALL;
		}
		else {
			gpu_select_mode = GPU_SELECT_ALL;
		}
	}
	else {
		if (do_passes) {
			gpu_select_mode = GPU_SELECT_NEAREST_FIRST_PASS;
		}
		else {
			gpu_select_mode = GPU_SELECT_ALL;
		}
	}

	/* Tools may request depth outside of regular drawing code. */
	UI_Theme_Store(&theme_state);
	UI_SetTheme(SPACE_VIEW3D, RGN_TYPE_WINDOW);

	/* Re-use cache (rect must be smaller then the cached)
	 * other context is assumed to be unchanged */
	if (GPU_select_is_cached()) {
		GPU_select_begin(buffer, bufsize, &rect, gpu_select_mode, 0);
		GPU_select_cache_load_id();
		hits = GPU_select_end();
		goto finally;
	}

	G.f |= G_PICKSEL;

	/* Important we use the 'viewmat' and don't re-calculate since
	 * the object & bone view locking takes 'rect' into account, see: T51629. */
	ED_view3d_draw_setup_view(vc->win, scene, ar, v3d, vc->rv3d->viewmat, NULL, &rect);

	if (v3d->drawtype > OB_WIRE) {
		v3d->zbuf = true;
		glEnable(GL_DEPTH_TEST);
	}

	if (vc->rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_set(vc->rv3d);

	GPU_select_begin(buffer, bufsize, &rect, gpu_select_mode, 0);

	ED_view3d_draw_select_loop(vc, scene, v3d, ar, use_obedit_skip, use_nearest);

	hits = GPU_select_end();

	/* second pass, to get the closest object to camera */
	if (do_passes && (hits > 0)) {
		GPU_select_begin(buffer, bufsize, &rect, GPU_SELECT_NEAREST_SECOND_PASS, hits);

		ED_view3d_draw_select_loop(vc, scene, v3d, ar, use_obedit_skip, use_nearest);

		GPU_select_end();
	}

	G.f &= ~G_PICKSEL;
	ED_view3d_draw_setup_view(vc->win, scene, ar, v3d, vc->rv3d->viewmat, NULL, NULL);

	if (v3d->drawtype > OB_WIRE) {
		v3d->zbuf = 0;
		glDisable(GL_DEPTH_TEST);
	}

	if (vc->rv3d->rflag & RV3D_CLIPPING)
		ED_view3d_clipping_disable();

finally:
	if (hits < 0) printf("Too many objects in select buffer\n");  /* XXX make error message */

	UI_Theme_Restore(&theme_state);

	return hits;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Local View Operators
 * \{ */

static unsigned int free_localbit(Main *bmain)
{
	unsigned int lay;
	ScrArea *sa;
	bScreen *sc;

	lay = 0;

	/* sometimes we loose a localview: when an area is closed */
	/* check all areas: which localviews are in use? */
	for (sc = bmain->screen.first; sc; sc = sc->id.next) {
		for (sa = sc->areabase.first; sa; sa = sa->next) {
			SpaceLink *sl = sa->spacedata.first;
			for (; sl; sl = sl->next) {
				if (sl->spacetype == SPACE_VIEW3D) {
					View3D *v3d = (View3D *) sl;
					lay |= v3d->lay;
				}
			}
		}
	}

	if ((lay & 0x01000000) == 0) return 0x01000000;
	if ((lay & 0x02000000) == 0) return 0x02000000;
	if ((lay & 0x04000000) == 0) return 0x04000000;
	if ((lay & 0x08000000) == 0) return 0x08000000;
	if ((lay & 0x10000000) == 0) return 0x10000000;
	if ((lay & 0x20000000) == 0) return 0x20000000;
	if ((lay & 0x40000000) == 0) return 0x40000000;
	if ((lay & 0x80000000) == 0) return 0x80000000;

	return 0;
}

int ED_view3d_scene_layer_set(int lay, const bool *values, int *active)
{
	int i, tot = 0;

	/* ensure we always have some layer selected */
	for (i = 0; i < 20; i++)
		if (values[i])
			tot++;

	if (tot == 0)
		return lay;

	for (i = 0; i < 20; i++) {

		if (active) {
			/* if this value has just been switched on, make that layer active */
			if (values[i] && (lay & (1 << i)) == 0) {
				*active = (1 << i);
			}
		}

		if (values[i]) lay |= (1 << i);
		else lay &= ~(1 << i);
	}

	/* ensure always an active layer */
	if (active && (lay & *active) == 0) {
		for (i = 0; i < 20; i++) {
			if (lay & (1 << i)) {
				*active = 1 << i;
				break;
			}
		}
	}

	return lay;
}

static bool view3d_localview_init(
        wmWindowManager *wm, wmWindow *win,
        Main *bmain, Scene *scene, ScrArea *sa, const int smooth_viewtx,
        ReportList *reports)
{
	View3D *v3d = sa->spacedata.first;
	Base *base;
	float min[3], max[3], box[3], mid[3];
	float size = 0.0f;
	unsigned int locallay;
	bool ok = false;

	if (v3d->localvd) {
		return ok;
	}

	INIT_MINMAX(min, max);

	locallay = free_localbit(bmain);

	if (locallay == 0) {
		BKE_report(reports, RPT_ERROR, "No more than 8 local views");
		ok = false;
	}
	else {
		if (scene->obedit) {
			BKE_object_minmax(scene->obedit, min, max, false);

			ok = true;

			BASACT->lay |= locallay;
			scene->obedit->lay = BASACT->lay;
		}
		else {
			for (base = FIRSTBASE; base; base = base->next) {
				if (TESTBASE(v3d, base)) {
					BKE_object_minmax(base->object, min, max, false);
					base->lay |= locallay;
					base->object->lay = base->lay;
					ok = true;
				}
			}
		}

		sub_v3_v3v3(box, max, min);
		size = max_fff(box[0], box[1], box[2]);
	}

	if (ok == true) {
		ARegion *ar;

		v3d->localvd = MEM_mallocN(sizeof(View3D), "localview");

		memcpy(v3d->localvd, v3d, sizeof(View3D));

		mid_v3_v3v3(mid, min, max);

		copy_v3_v3(v3d->cursor, mid);

		for (ar = sa->regionbase.first; ar; ar = ar->next) {
			if (ar->regiontype == RGN_TYPE_WINDOW) {
				RegionView3D *rv3d = ar->regiondata;
				bool ok_dist = true;

				/* new view values */
				Object *camera_old = NULL;
				float dist_new, ofs_new[3];

				rv3d->localvd = MEM_mallocN(sizeof(RegionView3D), "localview region");
				memcpy(rv3d->localvd, rv3d, sizeof(RegionView3D));

				negate_v3_v3(ofs_new, mid);

				if (rv3d->persp == RV3D_CAMOB) {
					rv3d->persp = RV3D_PERSP;
					camera_old = v3d->camera;
				}

				if (rv3d->persp == RV3D_ORTHO) {
					if (size < 0.0001f) {
						ok_dist = false;
					}
				}

				if (ok_dist) {
					dist_new = ED_view3d_radius_to_dist(v3d, ar, rv3d->persp, true, (size / 2) * VIEW3D_MARGIN);
					if (rv3d->persp == RV3D_PERSP) {
						/* don't zoom closer than the near clipping plane */
						dist_new = max_ff(dist_new, v3d->near * 1.5f);
					}
				}

				ED_view3d_smooth_view_ex(
				        wm, win, sa, v3d, ar, smooth_viewtx,
				            &(const V3D_SmoothParams) {
				                .camera_old = camera_old,
				                .ofs = ofs_new, .quat = rv3d->viewquat,
				                .dist = ok_dist ? &dist_new : NULL, .lens = &v3d->lens});
			}
		}

		v3d->lay = locallay;
	}
	else {
		/* clear flags */
		for (base = FIRSTBASE; base; base = base->next) {
			if (base->lay & locallay) {
				base->lay -= locallay;
				if (base->lay == 0) base->lay = v3d->layact;
				if (base->object != scene->obedit) base->flag |= SELECT;
				base->object->lay = base->lay;
			}
		}
	}

	DAG_on_visible_update(bmain, false);

	return ok;
}

static void restore_localviewdata(wmWindowManager *wm, wmWindow *win, Main *bmain, ScrArea *sa, const int smooth_viewtx)
{
	const bool free = true;
	ARegion *ar;
	View3D *v3d = sa->spacedata.first;
	Object *camera_old, *camera_new;

	if (v3d->localvd == NULL) return;

	camera_old = v3d->camera;
	camera_new = v3d->localvd->camera;

	v3d->lay = v3d->localvd->lay;
	v3d->layact = v3d->localvd->layact;
	v3d->drawtype = v3d->localvd->drawtype;
	v3d->camera = v3d->localvd->camera;

	if (free) {
		MEM_freeN(v3d->localvd);
		v3d->localvd = NULL;
	}

	for (ar = sa->regionbase.first; ar; ar = ar->next) {
		if (ar->regiontype == RGN_TYPE_WINDOW) {
			RegionView3D *rv3d = ar->regiondata;

			if (rv3d->localvd) {
				Object *camera_old_rv3d, *camera_new_rv3d;

				camera_old_rv3d = (rv3d->persp          == RV3D_CAMOB) ? camera_old : NULL;
				camera_new_rv3d = (rv3d->localvd->persp == RV3D_CAMOB) ? camera_new : NULL;

				rv3d->view = rv3d->localvd->view;
				rv3d->persp = rv3d->localvd->persp;
				rv3d->camzoom = rv3d->localvd->camzoom;

				ED_view3d_smooth_view_ex(
				        wm, win, sa,
				        v3d, ar, smooth_viewtx,
				        &(const V3D_SmoothParams) {
				            .camera_old = camera_old_rv3d, .camera = camera_new_rv3d,
				            .ofs = rv3d->localvd->ofs, .quat = rv3d->localvd->viewquat,
				            .dist = &rv3d->localvd->dist});

				if (free) {
					MEM_freeN(rv3d->localvd);
					rv3d->localvd = NULL;
				}
			}

			ED_view3d_shade_update(bmain, v3d, sa);
		}
	}
}

static bool view3d_localview_exit(
        wmWindowManager *wm, wmWindow *win,
        Main *bmain, Scene *scene, ScrArea *sa, const int smooth_viewtx)
{
	View3D *v3d = sa->spacedata.first;
	struct Base *base;
	unsigned int locallay;

	if (v3d->localvd) {

		locallay = v3d->lay & 0xFF000000;

		restore_localviewdata(wm, win, bmain, sa, smooth_viewtx);

		/* for when in other window the layers have changed */
		if (v3d->scenelock) v3d->lay = scene->lay;

		for (base = FIRSTBASE; base; base = base->next) {
			if (base->lay & locallay) {
				base->lay -= locallay;
				if (base->lay == 0) base->lay = v3d->layact;
				if (base->object != scene->obedit) {
					base->flag |= SELECT;
					base->object->flag |= SELECT;
				}
				base->object->lay = base->lay;
			}
		}

		DAG_on_visible_update(bmain, false);

		return true;
	}
	else {
		return false;
	}
}

static int localview_exec(bContext *C, wmOperator *op)
{
	const int smooth_viewtx = WM_operator_smooth_viewtx_get(op);
	wmWindowManager *wm = CTX_wm_manager(C);
	wmWindow *win = CTX_wm_window(C);
	Main *bmain = CTX_data_main(C);
	Scene *scene = CTX_data_scene(C);
	ScrArea *sa = CTX_wm_area(C);
	View3D *v3d = CTX_wm_view3d(C);
	bool changed;

	if (v3d->localvd) {
		changed = view3d_localview_exit(wm, win, bmain, scene, sa, smooth_viewtx);
	}
	else {
		changed = view3d_localview_init(wm, win, bmain, scene, sa, smooth_viewtx, op->reports);
	}

	if (changed) {
		DAG_id_type_tag(bmain, ID_OB);
		ED_area_tag_redraw(sa);

		/* unselected objects become selected when exiting */
		if (v3d->localvd == NULL) {
			WM_event_add_notifier(C, NC_SCENE | ND_OB_SELECT, scene);
		}

		return OPERATOR_FINISHED;
	}
	else {
		return OPERATOR_CANCELLED;
	}
}

void VIEW3D_OT_localview(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Local View";
	ot->description = "Toggle display of selected object(s) separately and centered in view";
	ot->idname = "VIEW3D_OT_localview";

	/* api callbacks */
	ot->exec = localview_exec;
	ot->flag = OPTYPE_UNDO; /* localview changes object layer bitflags */

	ot->poll = ED_operator_view3d_active;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Game Engine Operator
 *
 * Start the game engine (handles context switching).
 * \{ */

#ifdef WITH_GAMEENGINE

static ListBase queue_back;
static void game_engine_save_state(bContext *C, wmWindow *win)
{
	Main *bmain = CTX_data_main(C);
	Object *obact = CTX_data_active_object(C);

	glPushAttrib(GL_ALL_ATTRIB_BITS);

	if (obact && obact->mode & OB_MODE_TEXTURE_PAINT)
		GPU_paint_set_mipmap(bmain, 1);

	queue_back = win->queue;

	BLI_listbase_clear(&win->queue);
}

static void game_engine_restore_state(bContext *C, wmWindow *win)
{
	Main *bmain = CTX_data_main(C);
	Object *obact = CTX_data_active_object(C);

	if (obact && obact->mode & OB_MODE_TEXTURE_PAINT)
		GPU_paint_set_mipmap(bmain, 0);

	/* check because closing win can set to NULL */
	if (win) {
		win->queue = queue_back;
	}

	GPU_state_init();
	GPU_set_tpage(NULL, 0, 0);

	glPopAttrib();
}

/* was space_set_commmandline_options in 2.4x */
static void game_set_commmandline_options(GameData *gm)
{
	SYS_SystemHandle syshandle;
	int test;

	if ((syshandle = SYS_GetSystem())) {
		/* User defined settings */
		test = (U.gameflags & USER_DISABLE_MIPMAP);
		GPU_set_mipmap(G_MAIN, !test);
		SYS_WriteCommandLineInt(syshandle, "nomipmap", test);

		/* File specific settings: */
		/* Only test the first one. These two are switched
		 * simultaneously. */
		test = (gm->flag & GAME_SHOW_FRAMERATE);
		SYS_WriteCommandLineInt(syshandle, "show_framerate", test);
		SYS_WriteCommandLineInt(syshandle, "show_profile", test);

		test = (gm->flag & GAME_SHOW_DEBUG_PROPS);
		SYS_WriteCommandLineInt(syshandle, "show_properties", test);

		test = (gm->flag & GAME_SHOW_PHYSICS);
		SYS_WriteCommandLineInt(syshandle, "show_physics", test);

		test = (gm->flag & GAME_ENABLE_ALL_FRAMES);
		SYS_WriteCommandLineInt(syshandle, "fixedtime", test);

		test = (gm->flag & GAME_ENABLE_ANIMATION_RECORD);
		SYS_WriteCommandLineInt(syshandle, "animation_record", test);

		test = (gm->flag & GAME_IGNORE_DEPRECATION_WARNINGS);
		SYS_WriteCommandLineInt(syshandle, "ignore_deprecation_warnings", test);

		test = (gm->matmode == GAME_MAT_MULTITEX);
		SYS_WriteCommandLineInt(syshandle, "blender_material", test);
		test = (gm->matmode == GAME_MAT_GLSL);
		SYS_WriteCommandLineInt(syshandle, "blender_glsl_material", test);
		test = (gm->flag & GAME_DISPLAY_LISTS);
		SYS_WriteCommandLineInt(syshandle, "displaylists", test);


	}
}

#endif /* WITH_GAMEENGINE */

static bool game_engine_poll(bContext *C)
{
	bScreen *screen;
	/* we need a context and area to launch BGE
	 * it's a temporary solution to avoid crash at load time
	 * if we try to auto run the BGE. Ideally we want the
	 * context to be set as soon as we load the file. */

	if (CTX_wm_window(C) == NULL) return 0;
	if ((screen = CTX_wm_screen(C)) == NULL) return 0;

	if (CTX_data_mode_enum(C) != CTX_MODE_OBJECT)
		return 0;

	if (!BKE_scene_uses_blender_game(screen->scene))
		return 0;

	return 1;
}

static int game_engine_exec(bContext *C, wmOperator *op)
{
#ifdef WITH_GAMEENGINE
	Scene *startscene = CTX_data_scene(C);
	Main *bmain = CTX_data_main(C);
	ScrArea /* *sa, */ /* UNUSED */ *prevsa = CTX_wm_area(C);
	ARegion *ar, *prevar = CTX_wm_region(C);
	wmWindow *prevwin = CTX_wm_window(C);
	RegionView3D *rv3d;
	rcti cam_frame;

	UNUSED_VARS(op);

	/* bad context switch .. */
	if (!ED_view3d_context_activate(C))
		return OPERATOR_CANCELLED;

	/* redraw to hide any menus/popups, we don't go back to
	 * the window manager until after this operator exits */
	WM_redraw_windows(C);

	BLI_callback_exec(bmain, &startscene->id, BLI_CB_EVT_GAME_PRE);

	rv3d = CTX_wm_region_view3d(C);
	/* sa = CTX_wm_area(C); */ /* UNUSED */
	ar = CTX_wm_region(C);

	view3d_operator_needs_opengl(C);

	game_set_commmandline_options(&startscene->gm);

	if ((rv3d->persp == RV3D_CAMOB) &&
	    (startscene->gm.framing.type == SCE_GAMEFRAMING_BARS) &&
	    (startscene->gm.stereoflag != STEREO_DOME))
	{
		/* Letterbox */
		rctf cam_framef;
		ED_view3d_calc_camera_border(startscene, ar, CTX_wm_view3d(C), rv3d, &cam_framef, false);
		cam_frame.xmin = cam_framef.xmin + ar->winrct.xmin;
		cam_frame.xmax = cam_framef.xmax + ar->winrct.xmin;
		cam_frame.ymin = cam_framef.ymin + ar->winrct.ymin;
		cam_frame.ymax = cam_framef.ymax + ar->winrct.ymin;
		BLI_rcti_isect(&ar->winrct, &cam_frame, &cam_frame);
	}
	else {
		cam_frame.xmin = ar->winrct.xmin;
		cam_frame.xmax = ar->winrct.xmax;
		cam_frame.ymin = ar->winrct.ymin;
		cam_frame.ymax = ar->winrct.ymax;
	}


	game_engine_save_state(C, prevwin);

	StartKetsjiShell(C, ar, &cam_frame, 1);

	/* window wasnt closed while the BGE was running */
	if (BLI_findindex(&CTX_wm_manager(C)->windows, prevwin) == -1) {
		prevwin = NULL;
		CTX_wm_window_set(C, NULL);
	}

	ED_area_tag_redraw(CTX_wm_area(C));

	if (prevwin) {
		/* restore context, in case it changed in the meantime, for
		 * example by working in another window or closing it */
		CTX_wm_region_set(C, prevar);
		CTX_wm_window_set(C, prevwin);
		CTX_wm_area_set(C, prevsa);
	}

	game_engine_restore_state(C, prevwin);

	//XXX restore_all_scene_cfra(scene_cfra_store);
	BKE_scene_set_background(CTX_data_main(C), startscene);
	//XXX BKE_scene_update_for_newframe(bmain->eval_ctx, bmain, scene, scene->lay);

	BLI_callback_exec(bmain, &startscene->id, BLI_CB_EVT_GAME_POST);

	return OPERATOR_FINISHED;
#else
	UNUSED_VARS(C);
	BKE_report(op->reports, RPT_ERROR, "Game engine is disabled in this build");
	return OPERATOR_CANCELLED;
#endif
}

void VIEW3D_OT_game_start(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Start Game Engine";
	ot->description = "Start game engine";
	ot->idname = "VIEW3D_OT_game_start";

	/* api callbacks */
	ot->exec = game_engine_exec;

	ot->poll = game_engine_poll;
}

/** \} */
